Yes, unless you create a backup of your iPod before you restore it via iTunes. See here for what is included in the backup.
iTunes: About iOS backups
And information on how to backup your device.
iOS: How to back up
If these were synced photos, they won't be included in the backup that you can make via iTunes or iCloud, but since they originally were synced from your PC, they should still be there.
B-rock